The present invention relates to a mouse for a computer and, more particularly, to a mouse adapted for use by persons of either handedness.
One of the most common accessories for a personal computer (PC) is a mouse for translating motion of a user""s hand into signals that an attached PC can use to move a cursor or pointer on a display. Computer mice can be found in a variety of physical embodiments. Typically a mouse comprises a body that serves as a grip for the user""s hand and as a structure for mounting a movement sensing system and two or more mouse buttons for selecting computer functions. Mice are available with electro-mechanical, opto-mechanical, or optical movement sensing systems. The electro- and opto-mechanical systems typically incorporate a ball arranged for rotation in the body and protruding from the bottom of the mouse into contact with the surface on which the mouse is resting. Movement of the mouse causes the ball to rotate. Electrical or optical transducers in the body convert the motion of the ball into electrical signals proportionate to the extent of movement of the mouse in x and y directions. The motion of the mouse can also be sensed with an optical system. One optical system requires a special mouse pad with grid lines on a reflective surface. As the mouse is moved over the grid changes in the direction of reflected light are optically detected and transformed to electrical signals. Another mouse employs a digital camera to take periodic photographs of the surface on which the mouse is moved. A digital signal processor analyzes the series of images to determine the direction and extent of motion. Typically, the electrical signals generated by the movement sensing system are converted to a serial, digital data stream by a microprocessor in the mouse and sent to the computer over a cable or by infrared or radio frequency signaling. The computer uses the x and y movement data obtained from the mouse to repeatedly recalculate the position of the cursor on the display.
In addition to the movement sensing system, the mice are generally equipped with at least two mouse buttons for selecting and initiating computer functions. A mouse may be equipped with additional buttons and mice are available with other forms of user input devices, such as finger operated rollers that can be used to move a cursor in a displayed electronic document. Referring to FIG. 1, mouse buttons 10 and 12 are actuators for switches 14 and 16 within the body of the mouse. The switches 14 and 16 have normally-open and normally-closed input terminals connected to either a xe2x80x9chighxe2x80x9d 18 or xe2x80x9clowxe2x80x9d 20 voltage source. When the left button 10 is depressed, the normally open contacts of switch 14 are closed and the voltage at the output terminal 22 is switched from low to high. At the terminal 24 of the mouse microprocessor 26 which is electrically connected to output terminal 22 the voltage is likewise switched from low to high. When the mouse button 12 is depressed, the voltage at microprocessor terminal 28 will switch from low to high. Typically, the mouse microprocessor 26 converts the signals generated by the movement sensing system and the mouse button inputs to a serial, digital data stream which is sent to the computer. For example, whenever a mouse conforming to the requirements of an International Business Machines (IBM) PS/2 computer is moved or a mouse button is depressed, the mouse microprocessor sends three bytes of data to the computer. The second and third byte contain the x and y movement values and the first two bits of the first byte indicate the states (depressed or released) of the left 10 and right 12 mouse buttons, respectively.
Depressing or xe2x80x9cclickingxe2x80x9d a mouse button, signals the computer to initiate a function. The function is determined by the operating system and application program in use with the computer. For example, depressing or clicking the xe2x80x9cleftxe2x80x9d mouse button commonly causes the computer to select and change the state of the cursor on the display. As a result, the user of a word processing program may insert characters or take some other action at the cursor""s displayed location in a displayed electronic document. On the other hand, if the user holds the button in a depressed position and moves the mouse, the cursor can be xe2x80x9cdraggedxe2x80x9d over an xe2x80x9careaxe2x80x9d of the displayed document and that area can be selected for some common action. Depressing the xe2x80x9crightxe2x80x9d button may cause a context related menu to be displayed.
As the use of a mouse has become more universal, ergonomics has assumed an increasing role in mouse design. For example, mice can be obtained that are designed for either right-handed or left-handed users. Strand, U.S. Pat. No. 6,031,522 discloses an ergonomic mouse having a removable body shell. The shell fits over a base mouse that includes a movement sensing system and switches. Different shells can be installed on the base mouse to accommodate varying hand sizes, different handedness, or varying numbers of buttons for different computers, applications, or special user requirements. A mouse designed for either right or left-handed use improves user comfort and efficiency and may reduce injuries related to mouse use. Such a mouse is acceptable and desirable if the computer has a single user. However, in a home environment, a computer may be used concurrently by a number of users of different handedness. Likewise, in libraries, schools, and other applications where computer use is shared, a mouse shaped for ambidextrous use is highly desirable, if not necessary.
Standardization of the function associated with a particular mouse button is another ergonomic aspect of mouse design. One button is typically positioned for more convenient actuation by the index finger and a second button is positioned for actuation by the middle finger. Typically the cursor select function is assigned to the mouse button operated by the index finger because the function is the predominant function initiated by mouse operation. Standardization in function assignment increases the convenience of mouse operation and reduces learning time. However, standardization of function assignment presents a problem when a mouse is used by persons of different handedness. If a function is assigned to the left mouse button of a right-handed mouse (the button operated by the index finger of the right hand), a left-handed user of that mouse must actuate the button with the middle finger to obtain the same function. This operation may be awkward and is confusing if the user also operates a computer with a left-handed mouse. Computer operating systems typically provide for reassignment of functions for left and right-handed mice. While this is useful in maintaining the desired relationship between the finger used to initiate the function for right handed and left-handed mice, it increases user confusion if a mouse with an opposite button-function relationship is used. Further, many computer users may not be sufficiently familiar with the operating system to find and change the function-button relationship.
Moore, U.S. Pat, No. 4,816,810, discloses a remote acceptance switch that permits positioning the mouse with one hand and actuation of a remotely located mouse button with the second hand. Likewise, one could provide both left and right-hand mice and a selector switch to permit the user to choose the appropriate mouse. However, additional switches, cords, and mice on the work surface are not usually desirable.
What is desired, therefore, is a convenient way of switching the mouse button-computer function relationship so that a mouse can be conveniently configured for use by either hand.
The present invention overcomes the aforementioned drawbacks of the prior art by providing a mouse for a computer comprising a mouse switch for selectively initiating a first computer function and a selector to cause the mouse switch to initiate a second computer function. One embodiment of the invention uses a double pole, double throw switch to reverse the connections between mouse buttons and the corresponding mouse switch actuation signal terminals of the mouse microprocessor. As a result, the relationship of the mouse buttons to the switch state signals output to the computer are reversed. In a second embodiment, a switch provides a selector signal to the microprocessor software causing the microprocessor to signal the attached PC that a mouse button has actuated when the other button is actually actuated. As result, a function initiated by the attached PC in response to actuation of one mouse button can be initiated by the other mouse button maintaining a familiar button-to-function relationship for persons of either handedness.